Related Experiment Video
Updated: Aug 11, 2026

Assessment of Respiratory Function in Conscious Mice by Double-chamber Plethysmography
Published on: July 10, 2018
Overestimation of inspiratory upper airway resistance
Abstract:
Inspiratory resistance was found to be 10-50% larger than the expiratory in a model of the upper airways. This was most likely caused by a high kinetic energy component in the airstream close to the constriction reducing the lateral pressure in excess of what could be explained by the frictional pressure drop. Consequently, the inspiratory resistance was overestimated. During expiratory flow, on the other hand, the kinetic energy component at the same site in the trachea was smaller and similar to that in the mouthpiece resulting in an apparently adequate assessment of expiratory resistance. These results may explain why previous authors have found equal inspiratory and expiratory upper airway resistance although the vocal cords abduct during inspiration and adduct during expiration. Pressures obtained by means of the tracheal puncture appeared to be more reliable compared to those obtained from puncture of the cricothyroid membrane.
Related Concept Videos
Assessment of Ventilation I: Respiratory Rate
A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma.
Critical Guidelines for Assessing Ventilation:
Pressure Relationships in Thoracic Cavity
Breathing Mechanisms
Both intra-alveolar and intrapleural pressures rely on specific lung properties. The ability to breathe—allowing air to enter the lungs during...
Pulmonary Ventilation: Inhalation
Boyle's law becomes particularly pertinent when examining respiratory...
Factors Affecting Pulmonary Ventilation
Alveolar Surface Tension
The alveolar fluid lines the luminal surface of the alveoli and exerts a force called surface tension. This force is caused by the polar water molecules in the liquid being more strongly attracted to each...
Hyperpnea and Hyperventilation
Acute Respiratory Failure-III

